HID lamps are a type of electrical gas-discharge lamp comprising a translucent housing containing a set of metal electrodes and filled with gas and metal salts. When an electrical current is passed through the lamp circuit, an electric arc forms between the electrodes which heats and vaporizes the metal salts to form plasma that increases the light intensity of the arc.
In off-road vehicles (including, for example, snowmobiles and all-terrain vehicles), HID lamps can be a desirable alternative to conventional lamps, such as incandescent tungsten-halogen lamps. HID lamps may provide greater light intensity, higher energy efficiency, more desirable color temperature, and greater longevity than conventional lamps. There are available a number of commercially available HID lamps for off-road recreational vehicles having sealed ballasts that can be installed in place of conventional lamps.
At the same time, however, HID lamps typically have different electrical power requirements than conventional lamps. HID lamps typically require a relatively higher voltage pulse during the start up phase, followed by a relatively lower voltage during use. For example, an HID lamp suitable for use in an off-road vehicle may require a direct current (“DC”) of approximately 10 amperes (“amps”) and a voltage of 12 volts during the start-up phase of operation, and a current of approximately 6 amps and a voltage of no less than 9 volts following the start-up phase. In addition, the DC power supply should be stable for optimal performance, constant luminescence, and longevity of HID lamps.
The electrical systems of many off-road vehicles designed for conventional lamps are not well suited for HID lamps. Many off-road recreational vehicles do not have a battery and the electrical systems are solely stator powered. Some off-road recreational vehicles do have a battery, but frequently the battery is connected to only the cranking and charging systems and not the ignition or headlamp system. In either case, the ability of the off-road recreational vehicle to deliver the voltage pulse required to start up the HID lamp is very limited, especially if they are started simultaneously with the vehicle. One prior art solution involves directly wiring the battery (if there is one) to the HID lamps. This configuration may be sufficient to meet the start-up phase power requirements, but prolonged use of the HID lamp will rapidly drain the battery because the battery is intended to be wired only to the cranking and charging systems, and the charging system output is just enough to charge the battery. Also, a number of off-road recreational vehicles deliver alternating current (“AC”) to the head lamps. Although a rectifier can be used to convert DC power to AC power, such conversion may result in elevated voltage spikes and current instability, both of which can damage HID lamps.
A number of different ideas have been proposed to facilitate the use of HID lamps on off-road recreational vehicles. However, the known proposals, including directly wiring the battery to the HID lamps, work poorly, not at all, or compromise functionality. Accordingly, there is a need in the art for an apparatus, and a method for using HID lamps on recreational vehicles. Such method and apparatus would preferably ensure sufficient power supply upon start-up, mitigate the problem of rapid battery drain, and would facilitate a sufficient and steady flow of DC power to the HID lamps. It would also be beneficial if the apparatus were relatively simple for the end-user to install and use.